Balloon for preparing for and easing human birth

ABSTRACT

A balloon for preparing for and easing human birth, which balloon is located at least partly inside the vagina of the pregnant woman during application, has in the inflated condition an application region (P) between its outer end (A), which is provided with a fitting ( 1 ) for a flexible tube, and its vaginal portion with the largest diameter (D); the balloon is conically shaped in its application region (P); the application region (P) is disposed approximately within the middle third of the balloon length between an outer portion (a) and an inner portion (i) of the balloon; the cone angle β in the application region is 25° or smaller.

The invention relates to a balloon for preparing for and easing humanbirth, which balloon is located at least partly inside the vagina of thepregnant woman during application and which is substantially conicallyshaped in an application region between its outer, end, which isprovided with a fitting for a flexible tube, and its vaginal portionwith the largest diameter.

Such a balloon, which in the inflated condition has an elongate form,which is provided in a middle portion with a waist-like constriction, isdescribed in German Unexamined Application 19715724. During applicationthereof, the waist is disposed in the region of the orifice of the birthcanal. By activation of the musculature of the pelvic floor, thepregnant woman can exercise by pushing the balloon out of the vagina inpreparation for giving birth, and in this way simulate the process ofgiving birth. The portion of the balloon section located inside thevagina and tapering conically toward the waist then causes the orificeof the birth canal to dilate in a manner similar to that caused by theemerging head of a baby.

It has been found that the said conical portion is particularlyadvantageous in connection with the gymnastic effect of the balloon. Theobject of the present invention is therefore to enhance this effect evenmore by a suitable configuration of the balloon.

For this purpose it is provided according to the invention that theapplication region of the balloon adjoins the outer end of the crownregion of the balloon in a conical portion, where it extends between anouter portion and an inner portion of the balloon approximately withinthe middle third of the balloon length, and that the cone angle in theapplication region is 25° or smaller.

In this connection it is expedient for the cone angle to be between 5and 15° and the diameter of the balloon in the crown region to be about9 cm in the inflated condition, and for its length, measured from theinner end to the outer end of the application region, to be 10 to 15 cm.

In a balloon with such a configuration, there is provided a conical facethat is much longer than in the known balloon and that extends at leastover the entire application region thereof, the said region representingapproximately the middle third of the total balloon length. The outerportion of the balloon adjoining the outer end of the said middle thirdrepresents approximately the outer third of the balloon and expedientlyis also conically formed, such that it continues the cone of theapplication portion in the direction of decreasing diameter. Uponcommencement of the gymnastic exercises, this conical outer portion thenhas the effect that it leads gently to a steadily increasing extensioneffect during the pushing exercises and thus ensures almost painlessprogressive increase of the intensity of the exercise.

In order not to endanger the mouth of the womb, it is advisable that thepart of the balloon located inside the vagina have a length of less than15 cm in the inflated condition. In the maximally inflated condition,its largest diameter in the crown region between the application portionand the inner portion is 9 to 10 cm, corresponding to the size of thehead of a baby at birth.

The different methods for achieving the conical form of the balloon areevident from the embodiments of the empty balloon envelope or thejust-inflated balloon envelope specified in the dependent claims, theinternal pressure of the balloon corresponding to or being slightlyhigher than atmospheric pressure.

In principle, the shape of the balloon in the inflated condition can beachieved either by an appropriate variation in wall thickness along asubstantially cylindrical balloon shape or by a corresponding conicalenvelope shape. In the first case, it is essential that the envelopewall thickness decrease in the direction of increasing balloon diameter;in the second case, the cone angle of the envelope should beapproximately equal to that of the inflated balloon.

Finally, the shape of the inflated balloon can also be achieved byappropriate pre-stretching of the balloon. Because of the associatedoverextension effect or of the distention of the envelope materialbeyond the reversible limit of elasticity caused by stretching,preferential extension within the stretched portions takes place duringsubsequent inflation, and so any desired cross-sectional configurationsexpanding in the manner of a conical shape can be achieved.

The cone angle of the inflated balloon should preferably be smaller than25°. In practice, exercising subjects have found an angle of about 10°to bee an agreeable value, at which overextension of the muscle tissueis simultaneously avoided.

As material for the balloon there are preferably used thermoplasticelastomers or silicone rubbers, which have a favorable combination ofmechanical characteristics, material resistance and biocompatibility.Polyvinyl chloride is also suitable.

The invention will be explained hereinafter on the basis of severalpractical examples, wherein

FIG. 1 shows a longitudinal section through an inflated balloon,

FIG. 2 shows a longitudinal section through a balloon envelope withdifferent wall thicknesses,

FIG. 3 shows a longitudinal section through a conically preformedballoon envelope,

FIGS. 4 and 5 show envelope and balloon with stretched middle portion,

FIGS. 6 and 7 show a waisted balloon envelope and balloon.

FIG. 1 shows a longitudinal section through an inflated balloon B. Inthis condition its internal pressure p_(i) is higher than its externalpressure p_(a). In its maximally extended final form, balloon B has alargest diameter D of 9 to 10 cm, corresponding to the size of a baby'shead. Its length from its inner end I to its outer end A isapproximately 20 to 24 cm in the fully inflated condition. The overalllength of balloon B is divided into three portions, each amounting toabout one third of its length, namely an inner portion i between itscrown region with the largest diameter D and inner end I; a middleportion m between its inner portion i and an outer portion a, the saidmiddle portion m having substantially conical shape and corresponding toapplication region P of balloon B; outer portion a extends from middleportion m to outer end A of balloon B; as shown in FIG. 1 it is alsoconical, specifically forming a continuation of the conical shape ofmiddle portion m. At its outer end A, balloon B has a connecting fitting1 in the form of a flexible tube, stiffened by a tubular insert 2. Atapproximately the midpoint, tubular insert 2 has a shoulder 3, on theopposite sides of which there are attached connecting fitting 1 ofballoon B and the end of a flexible tube 4, which places balloon B incommunication with an inflation device (not illustrated), such as a handpump.

During application for the purpose of prebirth gymnastics, the pregnantwoman inserts the deflated balloon B into the vagina, after which shepumps it up to an increasing degree corresponding to the progress oftraining and, with end A located outside the vagina, presses against thevaginal orifice by exerting the musculature of the pelvic floor and thevaginal musculature. In the process, the conical form of balloon Bcauses, in the region of its application portion P, increasing dilationof the orifice of the birth channel. For this purpose a suitable coneangle for the balloon shape is smaller than 25°, preferably between 5and 15°, ideally about 10°.

FIG. 2 shows a longitudinal section through a marginally inflated butnot expanded balloon envelope H1, wherein the internal pressure p_(i)corresponds approximately to the external pressure p_(a). Thecylindrical circumferential wall of balloon envelope H1 is formed suchthat its wall thickness decreases from outer end A to inner end I. Ifballoon envelope H1 is inflated, the balloon becomes conically shapedover its entire length, with diameters increasing from outer end A toinner end I. In this case, the crown region of the balloon with thelargest diameter D is closer to inner end I than in the embodimentaccording to FIG. 1.

FIG. 3 shows a cross section through an elongate balloon envelope H2,which is substantially conically shaped over the entire length, with acone angle α of about 5 to 10°. The diagram according to FIG. 3 showsballoon envelope H2 with p_(i)=p_(a), or in other words with equalpressures inside and around the balloon envelope. Balloon envelope H2has constant wall thickness over the entire cross section. Because ofits conical initial shape, it yields a balloon shape correspondingapproximately to that of FIG. 1 when in the inflated condition.

Despite different initial parameters, therefore, balloon envelopes H1and H2 according to FIGS. 2 and 3 therefore achieve very similar balloonshapes when measured in their inflated condition in which p_(i)>p_(a).

FIG. 5 shows a partly inflated balloon envelope H3, wherein the envelopeis being stretched in the region of its middle portion, such that aconically shaped application region P is formed between its crown regionwith the largest diameter D and the upper end 5 of a retaining ring 6.The initial shape of envelope H3 is illustrated in FIG. 4, wherep_(i)=p_(a). In a manner similar to the embodiment according to FIG. 2,it is cylindrical over the entire length but, in contrast to FIG. 2, ithas constant wall thickness, corresponding to the conical envelope H2illustrated in FIG. 3. By stretching envelope H3 in application regionP, to produce the desired conical shape there when the balloon isinflated, there is no need to make an envelope with variable wallthickness, thus simplifying production. The stretching process alsoopens up the possibility of adjusting the cone angle β in applicationregion P to a value that can be selected between wide limits. Once theenvelope material has been stretched according to FIG. 5, the finalballoon shape obtained upon inflation of envelope H3 without theretaining form shown in FIG. 5 once again corresponds substantially tothat of FIG. 1. Thus, as was already the case for the versions accordingto FIGS. 2 and 3, there is no need to illustrate it.

An embodiment of a balloon whose shape differs slightly from that of theballoon according to FIG. 1 is illustrated in FIG. 7. Therein a slightconstriction 7 is visible in application region P, which corresponds tomiddle portion m. This is caused by the waist 8 present in the middleportion of the associated envelope H4 shown in FIG. 6. The approximatelyconical shape that the inflated balloon shown in FIG. 7 has overall inthe region of its middle portion m and of its outer portion a resultsfrom a larger wall thickness of envelope H4 in the region of its outerand middle portions, compared with its inner, approximately cylindricalportion, formed with constant wall thickness.

In the embodiment of the balloon according to FIG. 7, its constriction 7produces, during application, an increased resistance in expulsiondirection R because of the slight constriction 7 in the transitionregion from conical shape to inner portion i, or in other words to thecrown region of the balloon characterized by the largest diameter D.Thus this balloon shape makes it possible to establish a specifiedpressure point during expulsion of the balloon from the birth canal bythe musculature of the pelvic floor and vaginal musculature of thewoman, similar to the increased resistance upon penetration of thebaby's head through the orifice of the birth canal.

Furthermore, in the embodiment according to FIGS. 6 and 7, thepositioning of envelope H4 is particularly simple, in that it issufficient at first to introduce envelope H4 as far as waist 8 into thevagina. With increasing inflation of the balloon, waist 8 then shiftsfurther inward, so that application region P of the balloon illustratedin FIG. 7 is located immediately inside the vaginal orifice, whereasouter portion a of the balloon is located outside the vagina.

1. A balloon for preparing for and easing human birth, which balloon islocated at least partly inside the vagina of the pregnant woman duringapplication and which is substantially conically shaped in anapplication region (P) between its outer end (A), which is provided witha fitting (1) for a flexible tube, and its vaginal portion with thelargest diameter (D), wherein the application region (P) of the balloonadjoins the outer end of the crown region of the balloon in a conicalportion, where it extends between an outer portion (a) and an innerpotion (i) of the balloon approximately within the middle third of theballoon length, and in that the cone angle (β) in the application regionis 25° or smaller.
 2. A balloon according to claim 1, wherein the coneangle (β) is between 5 and 15° when the balloon is inflated.
 3. Aballoon according to claim 1, wherein, in the inflated condition, itsdiameter (D) in the crown region is about 9 cm and in that its length,measured from the inner end to the outer end of the application region(P), is 10 to 15 cm.
 4. A balloon according to claim 1, wherein itsunpressurized envelope (H1) has a wall thickness that decreases fromoutside to inside, at least the the application region.
 5. A balloonaccording to claim 4, wherein its unpressurized envelope (H1) has acylindrical shape when the external and internal pressures are equal,and in that the wall thickness of the envelope (H1) decreases fromoutside to inside.
 6. A balloon according to claim 1, wherein itsunpressurized envelope (H2), measured in the pressure condition of equalexternal and internal pressures, has a conical shape corresponding tothe application region (P).
 7. A balloon according to claim 1, whereinits unpressurized envelope (H3) is pre-stretched in the applicationregion (P), such that the application region (P) assumes, in theinflated condition of the balloon, a shape that flares from its outerportion (a) to its inner portion (i).
 8. A balloon according to claim 1,wherein its unpressurized envelope (H4), measured in the pressurecondition of equal external and internal pressures, is constricted inthe form of a waist in the application area (P), and in that the wallthickness in the outer portion of the envelope (H4) adjoining the waist(8) is larger than in the application area (P).
 9. A balloon accordingto claim 1, further comprising a connecting fitting (1) in the form of aflexible tube molded onto its outer end (A) and stiffened by a tubularinsert (2).
 10. A balloon for preparing for and casing human birth,which balloon is located at least partly inside the vagina of thepregnant woman during application and which is substantially conicallyshaped in an application region between its outer end and its vaginalportion with the largest diameter, wherein the application region of theballoon adjoins the outer end of the crown region of the balloon in aconical portion, where it extends between an outer portion and an innerportion of the balloon approximately within the middle third of theballoon length, and in that the cone angle in the application region is25° or smaller, and wherein, in the inflated condition, its largestdiameter in the crown region is about 9 cm and in that its length,measured from the inner end to the outer end of the application region,is 10 to 15 cm.